Keyboard transmitter



March 28; 1933. E. P. BANCROFT 4 1,902,943 I KEYBOARD TRANSMITTER FiledMay '1, 1931 2 Sheets-Sheet 1 INVENTOR ERWIN R BANCROFT ATTORNEY I March28, 1933. E. P; BANCROFT 1,902,

KEYBOARD TRANSMITTER Filed Ma 1, 1931 2 Sheets-Sheet 2 A V -m I I--- hm, i m l'm-mm7 Wfifl Jami:

ATTORNEY Qi: I INVENTOR I 'ERWIN a Bmcaon' Patented 28, I 1933 UNITEDSTATES PATEN'II OFFICE ERWIN P. BAN OF BROOKLYN,v NEW ZOE K, ASSIGNOR TINTERNATIONAL GOI- MUNICATIONS LABORATORIES, INC., OF NEW YORK, N. Y., ACORPORATION OF NEW YORK KEYBOARD TRANSMITTER My invention relates toimprovements in keyboard transmitter mechanism for transmitting codesignals, and more especially for use in connection with rintingtelegraphs.

In keyboard transmltters it has been customary when a key lever has beendepressed to set up a code combination for transmission to lock eitherthe key levers or the code bars, and maintain them in the lockedcondition until the transmission of the signal has been completed. Underthese conditions a second key lever cannot be depressed to set up asucceeding combination until' the combination set up by the first keylever has been transmitted and the mechanism'released.

The result is that very little time is allowed between the unlocking ofthe mechanism and the time at which transmission of the succeedingcharacter signal should start for the depression of the next key leverand difliculty is experienced by the operators in attaining a speed ofoperation closely approximating that at which the apparatus is set tooperate.

The object of my invention is to eliminate this fault by providing amechanism for reading off the code combination from the code bars at thebeginning of the transmission period and thereafter leaving both the keyand code bars free to be positioned in accordance with a new combinationto be transmitted. I further provide means whereby the code combinationto be transmitted after being read off from the code bars is stored inthe mechanism until the signals cocrl'responding thereto have beentransmitte Another object of my invention isto provide a startingmechanism such that the depression of a second key lever before thetransmission of the signals corresponding to the first key leverdepressed has been completed will'condition the same to start themechanism a second time even though the second ke lever be releasedbefore the completion o the first signal period. This allows the secondset of signals corresponding to the second key depressed to followthetransmission of the first set of impulses without loss of valuable linetime. a

Still anotherobject of my invention is to arrange the code bars operatedby the key with the selector bars or other part oftransmittingmechanism.

a This provides a keyboard wherein the keys can be depressed rapidl andby a very light touch as friction'is r uced-to a minimum and the springtensions to be overcome are extremely small being only such as tonormally hold the key bars but of engagement with the code bars.

' Other features of m invention will be apparent in the descriptionwhich follows.

Referring to the drawings Fig. 1 shows the startin mechanism;

Fig. 2 shows the essential features'of the code signalling mechanism;

Fig. 3 is a modific tion in part of Fig. 2.

Re erring to Fig. i

The shaft 22 upon which are mounted the various cams shown in Fig. 2also carries a 34 pivoted at 36. his dog 32, for operating the clutch,corresponds to sto X of Fi 4 and 10 of United States atent No.

17,725 to F. G. Greed, granted July 8, 1930,

although other'forms of standard clutch mechanism may be used.

The stop arm 34 is operated by the counterclockwise movement of thelever 38 about the pivot'39 under the influence of a link 40 connectedto the universal bail 31 on the keyboard. This bail is shown pivoted atpoints 45.

When the key lever 41 is depressed the projection 47 on the bail engagesthe inclined surface of the lever 40 at 48, causing the lever to rotateon the pivot 46 and thus causing the olperation of lever 38 and theengagement of t e pawl 49 with roller 35 on arm 34.: This pawl 49 ispivoted to the arm 38 at 50 and is held against the stop 51 by thetension spring 37. v

When the pawl 49 comes into engagement with roller 35 the opposite endof the sto arm 34 is forced out of engagement 22 to rotate. During theclockwise rotation released, thus releasing the universal bail 31, thepawl 49 rotates about pivot 50 and I does not depress roller 35. 5

A latch 44 pivoted at 54 is arranged to engage a projection 56 on stoparm 34 holding the transmission of the first code combina-.

it out of engagement with the stop dog 32 whenever the stop arm isoperated by the depression of roller 35. Pin 55 carried.- on the clutchhousing 32 is arranged to engage the bevelled surface 55 of latch'44which causes the latch to unlock or disengage the PIO]0- tion 56 andallow the arm 34 to assume its normal position after the shaft 22 hasrotated only a small fraction of a revolution.

The purpose of this latch is to lock the stop arm 34in a position so itwill not engage stop dog 32 if the universal bail 31 is operated asecond 'time before shaft 22 has completed its first revolution. I

An advanta e of this arrangement when applied to a eyboard transmitterof this type is that, not only is it possible to operate a second keylever before the transmission of the code impulse corresponding to thefirst key lever has been completed, but further that it is not necessaryto hold the second key lever operated until the completion of tion. Withsuch an arrangement it is possible to operate two key levers at anaverage speed in excess of five times the working speed of thetransmitter, or three key levers at an average 'speed of approximatelytwo and one-half times the working speed, or

v four key levers at something over one an one-half times the workinspeed. While this advantage is apprecia le for a large number ofletters, it is, of course, understood that over a period of time theaverage speed cannot exceed the normal operating speed of thetransmitter. However, this mechanism will allow for a considerableunevenness in 45 the operation of the keyboard and permit at the sametime the operator to approach very closely the operating speed at whichthe transmitter is set to operate.

Referring to Fig. 2, 42 represents one of fivecode bars having notchescut in such a manner that the depression of any .key bar or lever 41will force them into the desired position in accordance with the coderepresentingthat particular key lever. The code bars are five in numberin the arrangement shown, although it should be understood that therewill be one such for each element of the code with which the mechanismis desi ed to operate.

' hus, if the letter A-key bar is depressed,

the first'and second code bars may be moved to the right, and the third,fourth and fifth to the left. In front of each code bar is a lever orselector bar 2 all mounted on a pivot rod 3 supported in a cradle 5. Inaddition to the five code bars there is a sixth or unithe roller 4carried by the shaft 3 upon which are mounted the levers 2 which engagethe code bars 42.-

If one of the code bars is in front ofits corresponding lever 2, theleft-hand end of 2 will be prevented from moving, thus forcing theright-hand'end of this lever downward. If, however, the. code bar is notin front of its associated lever 2, the left-hand end will movedownward, while the right-hand end will be held in the position shown,by the tension spring 14'.

The shaft 22 carries two other cams 8, which engage rocker arms 18pivoted at 19.

The two arms 18 support a locking bar or bail 9 arranged to pass over orunder the ends of the levers 2 according to the position they haveassumed. The operation of the bar 9 by cams 8 is such-that when levers 2have taken their positions in accordance with the selection representedby the particular key lever depressed, levers 2 will be locked in thatposition. Thus, those levers 2 in front of which a code bar'42 has beenplaced will have their extreme right-hand end locked in the downwardposition, while those in front of which no code bar has been placed willbe lockedin the position shown. Cam 8 is so arranged that levers 2 willremain locked until near the end of the revolution of the cam shaft 22or until the completion of the code signal.

Cam 21 allows cradle 5' to return to normal as soon as levers 2 arelocked in their selected positions and thereby freeingall selector bars2 from contact with' code bars 42.

(lo-acting with these five cams and the five levers 2 are five levers 12pivoted on the bearmg rod 10. The levers '12 are normally held in theposition shown by the extensions on the levers 2 and the surfaces ofcams 7 During the revolution of the shaft 22, the lower extremity of thefive contact operating levers 12 will tend to move to the left or towardthe code bars 42, under the tension of springs 14..

Those levers 12 in front of which a projection of lever 2 is found willbe restrained from moving, while those having the exten sion on lever 2out of their path will be allowed to move. Any of the five levers 12 inoperating moves its associated arm 26. These arms are rigidly mounted ona common shaft they will operate their respective arms 26 and move lever16in a counter-clockwise direction causing the tongue 60 to engagecontact 61'. Those levers 12 not permitted to move will allow lever 16to move in a clockwise direction under influence of "springs 28 causingthe tongue 60' to engage contact 62. Since the five levers 12 operate insuccession causing tongue 60 to engage contacts 61 and 62 in succession,these contacts will 1 be closed in accordance with the code combinationrepresenting the particular key lever depressed. In order that contact62 may be closed after the signals representing each code combinationhave been transmitted a sixth lever 23 and a sixth cam 25' are provided.The cam has a detent or flat surface located so'the lever 23 is allowedto rotate clockwise to close contact 62 when the shaft 22 is in its stopposition.

- substantially the same as the apparatus shown in Fig. 2, except thatinFig. 3 the selector bars 2 control the operation of levers 12 throughthe medium of levers 7 7.

Corresponding parts of Fig. 3 are given the same reference numbers as inFig. 2. V The operation of code bars 42 by key levers (not shown in Fig.3) and the positioning of the selector bars 2 in their selected andnonselected positions is the same as in Fig. 2. When the selector bars 2move to their selected positions, the locking bail 9 is operated to holdthem in that osition. When those bars 2 whose ends 73 ave been forceddownward the projection 80 of bail 9 will pass over the surfaces 82 andholdthe m in their downward 'positions.

. ,The selector bars 2 which have not been.

moved downward will be held in their normal positions by the projections80 of the locking bail 9 moving into the notches 81 of the selector bars2.

When the selector bars 2 are locked in their determined positions thecradle 5 is allowed to return to normal position thereby freeing thecode bars42, which may then be set to other positions.

When the portion 73 of the selector bar 2 moves downward, the lower end76 oflatch bar 77 pivoted at 78 moves inward under the influence ofspring 87 and the upper end moves outward and disengages extensions 90of lever 12 to allow lever 12 to. be controlled by cam 7 in the samemanner as in Fig. 2. Forv those selector bars 2 which have not beenoperated, the latch 77 is not moved to release the portion 90 to allowlever osing of the contact tongue 60 on con- 1 1. A keyboard transmittercomprisin a plurality of depressible key levers for setting up signalcombinations, means for transmitting signals corresponding to thecombination set up by the depression of one of said key levers, meansunder control of the signal transmitting means for rendering another ofsaid key levers depressible for transmitting signals corresponding tocombinations set up by its depression and before all the signalscorresponding to the first combination have been transmitted.

2. A keyboard transmitter comprisin a plurality of depressible keylevers for setting k up signal'combinations, means for transmittingsignals corresponding to the combination set up by the depression of oneof said key levers, means under control of the signal transmitting meansfor rendering another ofsaidkey levers depressible for transmittingsignals corresponding to the combination set up by its depression andimmediately after the setting up of the first signal combination.

3. A keyboard transmitter .for transmitting signals comprising aplurality of keys, means for controllin the starting of the transmissionof said signals, means for lockin g said starting means when one of saidkeys 1 is operated, means for unlocking said start-- ing means after thetransmissionof impulses has started so it can again be locked by anotherkey independent of the transmission of said signals.

4. A keyboard transmitter for transmitting signals comprising aplurality of keys, mechanism for controlling the transmission of saidsignals, means for starting said mechanism when one of said keys isoperated, means for locking said starting means, and means for unlockingsaid starting means after the 'transmission of signals has started, soit may be locked again by a' second key independently of thetransmission of said signals started by the operation of the first saidkey. 5. A keyboard transmitter comprising aplurality of depressible kelevers, a plurality of code bars engageabley said key levers whendepressed, selector bars having no mechanical connection with said codebars,

means for causing said code bars to become associated with said selectorbars in combinations according to the key lever depressed, andtransmitting contact operating means controlled by the selector bars.

6. A keyboard transmitter comprising a plurality of movable selectorbars, a 'plu- 'rality of movable code bars entirely disconpluralitofmovable selector bars, a plurality 0 code barshavingunrestrainedrnovement in two directions, means for moving said code barsin one direction in the'pat-h of said selector bars and in anotherdirection. away from saidselector bars, and transmitting contactoperating means controlled by v the selector bars.

8. A device comprising a plurality of code bars and correspondingselector bars mechanically disconnected therefrom, means for selecting.a combination of said codebars, means fortransferring the combinationselected to said selector bars, a transmitter contact ogeratinglevercontrolled byeach selector ar, and means for controlling said operatinglevers in sequence in accordance with {)he combination transferred tosaid selector ars.

9. A device comprising a plurality of movable code bars andcorresponding movable selector bars mechanically disconnected therefrom,means for positioning said c'ode bars, means controlled by thepositioning of said code bars to determine the position of said selectorbars transmitting. contact operating means controlled by the selectorbars, and. means to lock said selector bars in'their determinedpositions so said code bars maybe moved to other positions.

10. A- device comprising a plurality of movable code bars and aplurality of movable selector bars, means for positioning'said codebars, means to move said selector bars to positions determined by thepositions of.

said code bars, and means to lock said selector bars in their determinedpositions so said code' bars may be movedto other positions. v

11. A device comprising an operating mechanism, means for controllingthe operationof said mechanism, means for operating said controllingmeans to cause said mechanism tofperform one complete operation, and,means for allowing said controlling means to be again'operated beforethe mechanism has completed its first operation so both operations willbe continuous.

12. device comprising an operating mechanism, means for starting theoperation of said mechanism, means for stopping the operation of saidmechanism afterit has.per-' 'formed'one complete operation, means foroperating said starting means to caum the r' operation of saidmechanism, and means. for

vallowing said starting means to be again opelated before theperforinairce of its firftopmeans for. setting up said means including alock controlled by the ro- Y tary cam member to lock the selectorelements in set position and free'the permutation elements for anothersetting during the transmission of the code combination locked on theselector elements.

14. A keyboard transmitter for transmitting signals made up ofa startingimpulse, a plurality of selecting impulses and a stop impulse,comprising a plurality of keys, permutation code mechanism'set by theoperation of any of the keys and controlling the combinations ofselecting impulses 'to be transmitted, a driving shaft, a driven shaft,:1. single revolution clutch for coupling the shafts, means controlledby and during the rotation of the driven shaft to transmit the startingimpulses, t e selecting impulses as determined by the se ting of thecode mec anism and the stop impulse, a latch normally holding the clutchdisengaged, means responsive to the operation of any key to operate thelatch and allow the clutch to engage, means effective upon operation ofthe latch to lock it in operated position, means'controlled by thedriven shaft to release the locking means before transmission of thestop impulse and allow the latch to return to normal position so that itmay again be operated-and locked in response to the operation of any ofthe keys before completion of transmission of the selooting impulses.- I

15. A keyboard transmitter for transmitting signals made u of ,astarting impulse,

a plurality of selecting impulses and a stop (determined by the settingof the c e mechaholding the. clutch disen aged, means respom sive to theoperation 0 any key to operate the latch. and allow the clutch toengage,

msm and the stop impulse, a latchnormally I means effective uponoperationof the latch lecting impulses represented, by the to lock it inoperated position, and means of the selectors. I

controlled by the driven shaft and operating In witness whereof, Ihereunto subscribe during the transmission of the starting immy namethis th da of April, 1931.

pulse to release the locking means thereb ER N P. BANCROFT;

allowing the latch to return to normal position so that it may a aiu beoperated and locked in response to t e operation of any of the keysbefore completion of the transmission' of the selecting impulses.' p

16. A ke board transmitter comprisin a plurality 0? keys, a plurality ofpermutation.

asset in different combinations b operation of the various keys, auniversa bar invariably operated by the operation of any of 86 the keys,selector bars correspondin in number to the number of permutation arsand pivotally mounted intermediate their ends, a rotary cam memberstarted in rotation by operation of the universal bar and having asection for causing the selector bars to tilt in one direction or theother according to the setting of the permiltation bars, a locking barpositioned under control of the rotary cam member to lock the selectorbars in their tilted position, a series of successivelyoperatcd sectionson said rotary cam member corresponding respectively to the selectorbars,

and transmitter contact means operated 'under control of thesuccessivelv operated sec- 1 tions as determined by the ti ted position of the resective selector bars.

17. keyboard transmitter comprising a plurality of keys, a set ofpermutation members variously positioned by the operation of the keys, apivotally mounted cradle, a set of selectorbars pivoted on said cradle,

' transmitter contacts, and a rotary cam set in operation upon actuationof any key and having a section for invariably rocking the cradle aboutits pivot thereby to cause the selector bars to assume positionsdetermined b the setting of the permutation members'an having a seriesof successively operative sections 45 for controlling the operation ofthe transmitter contacts in accordance with the positioning of theselector bars.

18. A keyboard transmitter comprising a a s plurality of keys,a set ofpermutation memi i bers variously positioned by the operation of thekeys, a pivotally mounted cradle, a set of selectors pivoted on saidcradle, a rotary.

cam set in operation upon actuation of any 55 key to rock said cradleabout its pivot there- 7 by to cause the selectors to assume setpositions determined by the setting of the'permutation members, alocking bar controlled by the rotary cam to lock the selectors in set Va so position, transmitter contacts under control Y '125 of the rotarycam and the selectors, and means to restore the cradle to normalposition with the selectors locked in set 'tion thereb to free thepermutation mem rs for V as re-posltioning before transmission of the seI 139

